To manage network load, long term evolution (LTE) networks may access bar cells for UEs of specific access classes (ACs) or types of mobile originated (MO) traffic at the radio resource control (RRC) layer. For example, a network can prevent or restrict wireless devices from attempting to access the network by broadcasting access restriction parameters via ‘System information’, such as Master Information Block (MIB) and System Information Block type k (k=1, 2, . . . ). Specifically, the LTE network can restrict access for certain classes of UEs using control information for Access Class Barring (ACB), Service Specific Access Class Barring (SSAC) and Extended Access Barring (EAB). For ACB, a SIB2 may include ACB parameters for at least one of Emergency, MO data, Circuit-switched Fallback (CSFB), and MO signaling. The parameters for CSFB, MO-Data and MO-Signaling include a probability factor and a barring time for AC 0-9 and barring bits for access classes 11-15. For AC 0-9, if the UE initiates an MO call and the relevant parameters are included for the type of call, the UE generates a random number if the relevant access class barring timer is not already running. If the drawn number is lower than the value indicated by the probability, the UE may attempt to access the network. Otherwise, the UE is barred from attempting to access the network for a duration which is randomly selected based on the broadcasted barring time value.
If access barring is configured by the network, the SIB2 includes relevant parameters such as type of connection request for which barring is in effect and associating barring time. Examples of types of connections which may be barred along with barring time are ac-BarringForEmergency, ac-BarringForMO-Data (T303), ac-BarringForCSFB (T306/T303), and ac-BarringForMO-Signalling (T305). In summary, the access classing configuration specifies a probability of barring (ac-BarringFactor) the call origination on the user equipment (UE) and a formula to generate the timeout value before calls can be attempted, i.e., a new random number is generated and compared to the probability.
Like reference symbols in the various drawings indicate like elements.